ANSI/ISA-95 (commonly called ISA-95) is the international standard for developing an automated interface between enterprise systems and control systems. Published by the International Society of Automation and adopted as IEC 62264, ISA-95 provides a consistent framework for integrating manufacturing operations with business planning and logistics. For organizations pursuing digital transformation, ISA-95 is the foundational reference model that defines what information must flow between the plant floor and the enterprise.
The Purdue Enterprise Reference Architecture
ISA-95 is built upon the Purdue model, which defines a hierarchical functional model of manufacturing operations. The model separates enterprise and control functions into distinct levels:
Level 4 — Business Planning & Logistics
┌─────────────────────────────────────────┐
│ ERP (Enterprise Resource Planning) │
│ Order processing, production scheduling, │
│ shipping, material procurement │
└──────────────────┬──────────────────────┘
│ (business data)
Level 3 — Manufacturing Operations Management
┌──────────────────┴──────────────────────┐
│ MES (Manufacturing Execution System) │
│ Production tracking, quality management, │
│ maintenance management, performance │
│ analysis, work dispatching │
└──────────────────┬──────────────────────┘
│ (production data)
Level 2 — Supervisory Control
┌──────────────────┴──────────────────────┐
│ SCADA, HMI, batch control, engineering │
│ workstations, alarm management │
└──────────────────┬──────────────────────┘
│ (supervisory data)
Level 1 — Basic Control
┌──────────────────┴──────────────────────┐
│ PLC, DCS, SIS, RTU, CNC controllers │
└──────────────────┬──────────────────────┘
│ (process data)
Level 0 — Physical Process
┌──────────────────┴──────────────────────┐
│ Sensors, actuators, motors, valves, │
│ field instruments │
└─────────────────────────────────────────┘ISA-95 Standard Parts
The ISA-95 standard is organized into multiple parts, each addressing a specific aspect of enterprise-control integration:
| Part | Title | Status | Focus |
|---|---|---|---|
| Part 1 | Models and Terminology | Published (IEC 62264-1) | Defines consistent terminology, hierarchy models, functional data flow, object models, and operations activity models. |
| Part 2 | Object Model Attributes | Published (IEC 62264-2) | Defines attributes for every object in Part 1. Used as the basis for information exchange and relational databases. |
| Part 3 | Models of Manufacturing Operations Management | Published (IEC 62264-3) | Focuses on Level 3 activities (MES layer). Defines production, quality, maintenance, and inventory operations. |
| Part 4 | Object Models and Attributes for MOM | Published (IEC 62264-4) | Defines object models for information exchange between MES activities. |
| Part 5 | Business-to-Manufacturing Transactions | Published (IEC 62264-5) | Defines transactions between enterprise and manufacturing systems. |
ISA-95 Object Models
ISA-95 Part 1 defines a set of object models that categorize the elements of manufacturing operations:
- Personnel Model — Qualified personnel, certifications, and roles.
- Equipment Model — Physical and logical equipment hierarchy (enterprise, site, area, process cell, unit, equipment module, control module).
- Material Model — Material classes, material lots, material definitions, and material sub-lots.
- Process Segment Model — Segments of the manufacturing process that define what equipment and materials are used.
- Production Schedule and Performance — Production requests, production rules, and actual performance data.
- Operations Definition and Schedule — Detailed manufacturing operations and their sequencing.
B2MML — Business To Manufacturing Markup Language
B2MML is an XML implementation of the ISA-95 standard, maintained by the Manufacturing Enterprise Solutions Association (MESA). It provides a standardized schema for exchanging ISA-95-defined information between systems such as ERP, MES, and control systems. B2MML enables:
- Standardized data exchange between SAP ERP and plant-floor systems.
- Interoperability between MES platforms from different vendors.
- Consistent object model representation across the enterprise.
- Reduced integration engineering effort through pre-defined schemas.
Practical Implementation
Implementing ISA-95 in an industrial environment typically involves:
- Define the equipment hierarchy — Map physical assets to the ISA-95 model (enterprise → site → area → process cell → unit).
- Identify information flows — Determine what data must move between each level (production schedules downward, production results upward).
- Select integration technology — OPC UA (with ISA-95 companion specifications), MQTT, REST APIs, or middleware platforms.
- Map object models — Define how material, equipment, and personnel data is structured and exchanged.
- Implement transactions — Configure production schedules, work orders, material consumption, and quality results exchange.
ASP OTOMASYON designs and implements ISA-95-aligned integration architectures for Turkish manufacturers, connecting plant-floor control systems with ERP and MES platforms using OPC UA and modern middleware solutions.